WHAT TO SPOT
Natural wonders to watch out for this week …
It was a few days ago on what felt like the first warm night of the year when I heard them. That telltale scream which led to them once being nicknamed the “Devil’s bird” echoed about the sky.
There were perhaps a dozen or so, hawking for insects floating in the thermals. “The swifts are back, the swifts are back… ” I shouted to nobody in particular.
It is a refrain that echoes down the ages. “They’ve made it again, which means the globe’s still working,” the poet Ted Hughes famously wrote of the birds’ return to these shores from their epic sub-Saharan migration.
The swift migrates to Britain from Africa to breed each summer, a journey spanning some 6,000 miles. It is a mammoth odyssey, but one for which the swift is perfectly adapted, as its boomerang-shaped wings make it the fastest bird in powered flight ever recorded.
While the peregrine falcon achieves higher speeds, that is the result of the raptor stooping (essentially plummeting down from a great height) rather than beating its wings.
Swifts never touch down, apart from to land on their nests, and they even feed on the go: on a good day a pair can gobble up 20,000 insects and spiders between them.
They also possess a powerful migratory instinct, one that we do not yet fully understand. Pairs mate for life and meet up each spring at the same nesting site.
The birds that I spotted a few days ago always occupy the same nests in the crumbling masonry of some old houses overlooking a tennis court where I play on summer evenings. And in many cases they will be the very same birds, as swifts live for an average of 10 years.
That familiarity is precisely why swifts mean so much to us: they are woven into the fabric of our every year.
Swifts construct their nests on a ledge or overhang out of mud, which is then glued together with the bird’s saliva. Normally this will be high up in a roof crevice or under a roof tile. Home renovations can prove disastrous to swifts as modern methods of repair can leave little room for the birds to thrive.
That is one of the main reasons why nationally their numbers have fallen by about 50 per cent since 1995.
However, it is possible to help the birds by installing swift boxes high up in the eaves of a house – but they need to be as vertiginous as possible. Height, for a bird that can comfortably coast at 10,000ft, even while it is sleeping, means everything.
Perhaps the ideal nesting location for swifts is the tower of the Oxford Museum of Natural History. A steep arching turret studded with ventilation flues, the colony of swifts which return to breed here each year has been monitored since 1949 – making it one of the longest-recorded continuous studies of any species of bird in the world.
Here, too, the birds have now returned. On Tuesday May 5, following a bank holiday of strong north-easterly winds and heavy rain, the sun came out and the first two swifts of the year were sighted. The date means the birds are exactly on time.
And yet that time together is always too swift.
By August the birds will have gone, heading back to the forests of central Africa. And the screaming skies will have fallen still for another year.